scholarly journals The Relationship between Photometric Measurements and Visual Magnitude Estimates for Red Stars

2021 ◽  
Vol 161 (2) ◽  
pp. 75
Author(s):  
Robert R. Cadmus
Keyword(s):  
Visual Magnitude ◽  
Photometric Measurements ◽  
The Relationship ◽  
Magnitude Estimates

Reaction Time and Visual Brightness: Within-Subject Correlations

1979 ◽  
Vol 48 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Armand V. Cardello
Keyword(s):  
Reaction Time ◽  
Stimulus Intensity ◽  
Reaction Times ◽  
Visual Reaction Time ◽  
Visual Reaction ◽  
Two Measures ◽  
The Relationship ◽  
Linear Correlations ◽  
Visual Brightness ◽  
Magnitude Estimates

An experiment was conducted to compare visual reaction time and visual brightness within the same subjects. Simple reaction times and magnitude estimates of brightness were obtained in response to 1000-msec. flashes of 60.7, 67.5, 76.4, 85.1, and 93.4 dB re 10−10L white light. The relationship between reaction time and stimulus intensity was best described by a negative logarithmic function, while the relationship between magnitude estimates of brightness and stimulus intensity was best described by a power function. Linear correlations between reaction times and magnitude estimates indicated that visual reaction time and brightness are not proportional within all subjects. Previous reports of proportionality between these two measures were discussed as possibly being the result of inappropriate cross-experiment comparisons.

Relationship between direct-potentiometric and flame-photometric measurement of sodium in blood.

1982 ◽  
Vol 28 (9) ◽  
pp. 1931-1935 ◽  
Author(s):  
F S Apple ◽  
D D Koch ◽  
S Graves ◽  
J H Ladenson
Keyword(s):  
Water Content ◽  
Model Systems ◽  
Develop Model ◽  
Water Binding ◽  
Ph Dependency ◽  
Calibration Problem ◽  
Human Sera ◽  
Photometric Measurements ◽  
Measurement Artifact ◽  
The Relationship

Abstract The relationship between direct-potentiometric and flame-photometric measurements of sodium has been studied in human sera and other, simpler systems. When water content was varied by using an inert substance (silica), de-ionized sera, or de-ionized individual proteins, the percentage that the flame photometric values were of the direct potentiometric Na+ values was identical to the measured water content. However, in 35 patients the percentage of Na+ values was 99.1% and the water content was 92.0%, a discrepancy of 7.1%. De-ionization of sera removed this discrepancy, apparently because of the lower pH of the de-ionized sera. The percentage of flame-photometric to direct-potentiometric Na+ values varied as a function of pH in pooled sera; in lyophilized and reconstituted sera; and in de-ionized, lyophilized, and reconstituted sera. Four explanations for the discrepancy between the percentage of Na+ values and the water content are discussed: a calibration problem, a measurement artifact, Na+ binding, and water binding. At this time there are no definitive data concerning which explanation is correct. We expect that our finding of a pH dependency for the percentage of measured Na+ values can be used to develop model systems to elucidate the mechanism producing the discrepancy between the percentage of Na+ values and the water content.

scholarly journals HM Sge still evolving

1990 ◽  
Vol 122 ◽  
pp. 433-434
Author(s):  
H. Nussbaumer ◽  
M. Vogel
Keyword(s):  
Planetary Nebulae ◽  
Red Giants ◽  
Symbiotic Stars ◽  
High Brightness ◽  
X Ray ◽  
Secondary Maximum ◽  
Level Of Activity ◽  
General Decline ◽  
Visual Magnitude ◽  
Magnitude Estimates

In their study on C/N/O abundances in red giants, planetary nebulae, novae and symbiotic stars Nussbaumer, Schild, Schmid and Vogel (1988: Astron.Astrophys.198, 179) pointed out that among symbiotic stars HM Sge is quite exceptional, in that its C/N/O abundance ratios rather resemble those of novae and not of symbiotic stars.In 1975 HM Sge brightened within a few months by at least 4m. The object has been observed in radio, visual, X-ray, and since 1978 with IUE. Here we show the changing level of activity in the UV. Figure 1 gives the FES (IUE fine error sensor) counts, representing an integrated flux at visual wavelengths. This flux shows a general decline with a secondary maximum in 1982. – Our mFES is at variance with the visual magnitude estimates given by Munari and Whitelock (1989: Mon.Not.Roy.astr.Soc. 237, 45p). They report high brightness up to at least the end of 1984.

scholarly journals Parker Solar Probe Observations of a Dust Trail in the Orbit of 3200 Phaethon

2020 ◽  
Author(s):  
Karl Battams ◽  
Guillermo Stenborg ◽  
Russell Howard ◽  
Brendan Gallagher ◽  
Matthew Knight ◽  
...  
Keyword(s):  
White Light ◽  
Surface Brightness ◽  
Meteor Shower ◽  
Physical Parameters ◽  
Wide Field ◽  
Trail Following ◽  
Dust Trail ◽  
Visual Magnitude ◽  
Relationship Of ◽  
The Relationship

<p>We present details on the first white-light detection of a dust trail following the orbit of asteroid 3200 Phaethon, seen in images recorded by the Wide-field Imager for Parker Solar Probe (WISPR) instrument on the NASA Parker Solar Probe (PSP) mission. In this talk we will present a brief introduction to the PSP mission and the WISPR instrument. We will then show observations returned by WISPR in multiple perihelion 'encounters' that clearly show a diffuse dust trail perfectly aligned with the perihelion portion of the orbit of 3200 Phaethon, recorded while the asteroid itself was near aphelion. We will discuss the physical parameters that we have derived for the dust trail, including its visual magnitude, surface brightness and mass. We also speculate on the relationship of this trail to the Geminid meteor shower, of which Phaethon is assumed to be the parent, and demonstrate why the trail has not been detected visually until now, despite a number of dedicated observing campaigns. We also hope to present initial analyses of the most recent set of WISPR observations (January 2020), where we anticipate the trail should again be visible in the WISPR observations.</p>

Interstellar gas in the central region of the Galaxy

1967 ◽  
Vol 31 ◽  
pp. 239-251 ◽  
Author(s):  
F. J. Kerr
Keyword(s):  
Central Region ◽  
Galactic Plane ◽  
Neutral Hydrogen ◽  
Continuum Emission ◽  
Galactic Centre ◽  
Interstellar Gas ◽  
Hydrogen Recombination ◽  
The Galaxy ◽  
Centre Region ◽  
The Relationship

A review is given of information on the galactic-centre region obtained from recent observations of the 21-cm line from neutral hydrogen, the 18-cm group of OH lines, a hydrogen recombination line at 6 cm wavelength, and the continuum emission from ionized hydrogen.Both inward and outward motions are important in this region, in addition to rotation. Several types of observation indicate the presence of material in features inclined to the galactic plane. The relationship between the H and OH concentrations is not yet clear, but a rough picture of the central region can be proposed.

Probable Structure and Nature of the Formations on the Reverse Side of the Moon According to Photometric Measurements of Lunar Photographs

1962 ◽  
Vol 14 ◽  
pp. 39-44
Author(s):  
A. V. Markov
Keyword(s):  
The Moon ◽  
Probable Structure ◽  
The Earth ◽  
Interplanetary Station ◽  
Photometric Measurements ◽  
Automatic Interplanetary Station

Notwithstanding the fact that a number of defects and distortions, introduced in transmission of the images of the latter to the Earth, mar the negatives of the reverse side of the Moon, indirectly obtained on 7 October 1959 by the automatic interplanetary station (AIS), it was possible to use the photometric measurements of the secondary (terrestrial) positives of the reverse side of the Moon in the experiment of the first comparison of the characteristics of the surfaces of the visible and invisible hemispheres of the Moon.

The relationship of the scleractinian corals to the rugose corals

Paleobiology ◽  
1980 ◽  
Vol 6 (02) ◽  
pp. 146-160 ◽  
Author(s):  
William A. Oliver
Keyword(s):  
Critical Points ◽  
Scleractinian Corals ◽  
Convincing Evidence ◽  
Early Triassic ◽  
Rugose Corals ◽  
History Of ◽  
The Subject ◽  
Relationship Of ◽  
The Relationship ◽  
Biologic Factors

The Mesozoic-Cenozoic coral Order Scleractinia has been suggested to have originated or evolved (1) by direct descent from the Paleozoic Order Rugosa or (2) by the development of a skeleton in members of one of the anemone groups that probably have existed throughout Phanerozoic time. In spite of much work on the subject, advocates of the direct descent hypothesis have failed to find convincing evidence of this relationship. Critical points are:(1) Rugosan septal insertion is serial; Scleractinian insertion is cyclic; no intermediate stages have been demonstrated. Apparent intermediates are Scleractinia having bilateral cyclic insertion or teratological Rugosa.(2) There is convincing evidence that the skeletons of many Rugosa were calcitic and none are known to be or to have been aragonitic. In contrast, the skeletons of all living Scleractinia are aragonitic and there is evidence that fossil Scleractinia were aragonitic also. The mineralogic difference is almost certainly due to intrinsic biologic factors.(3) No early Triassic corals of either group are known. This fact is not compelling (by itself) but is important in connection with points 1 and 2, because, given direct descent, both changes took place during this only stage in the history of the two groups in which there are no known corals.

Choosing a Markov blanket

2020 ◽  
Vol 43 ◽  
Author(s):  
Thomas Parr
Keyword(s):  
Markov Blanket ◽  
Target Article ◽  
The Relationship

Abstract This commentary focuses upon the relationship between two themes in the target article: the ways in which a Markov blanket may be defined and the role of precision and salience in mediating the interactions between what is internal and external to a system. These each rest upon the different perspectives we might take while “choosing” a Markov blanket.

Tinkering with cognitive gadgets: Cultural evolutionary psychology meets active inference

2019 ◽  
Vol 42 ◽  
Author(s):  
Paul Benjamin Badcock ◽  
Axel Constant ◽  
Maxwell James Désormeau Ramstead
Keyword(s):  
Evolutionary Psychology ◽  
Research Program ◽  
Active Inference ◽  
Innovative Research ◽  
Cognitive Faculties ◽  
Cultural Evolutionary ◽  
The Relationship

Abstract Cognitive Gadgets offers a new, convincing perspective on the origins of our distinctive cognitive faculties, coupled with a clear, innovative research program. Although we broadly endorse Heyes’ ideas, we raise some concerns about her characterisation of evolutionary psychology and the relationship between biology and culture, before discussing the potential fruits of examining cognitive gadgets through the lens of active inference.

Radiation Damage, Contrast and Statistics in High Resolution Biological Electron Microscopy

1970 ◽  
Vol 28 ◽  
pp. 260-261
Author(s):  
Robert M. Glaeser
Keyword(s):  
High Resolution ◽  
Particle Flux ◽  
Unit Area ◽  
Signal To Noise ◽  
Resolution Image ◽  
High Resolution Image ◽  
Pass Through ◽  
Counting Statistics ◽  
The Relationship ◽  
Picture Element

It is well known that a large flux of electrons must pass through a specimen in order to obtain a high resolution image while a smaller particle flux is satisfactory for a low resolution image. The minimum particle flux that is required depends upon the contrast in the image and the signal-to-noise (S/N) ratio at which the data are considered acceptable. For a given S/N associated with statistical fluxtuations, the relationship between contrast and “counting statistics” is s131_eqn1, where C = contrast; r2 is the area of a picture element corresponding to the resolution, r; N is the number of electrons incident per unit area of the specimen; f is the fraction of electrons that contribute to formation of the image, relative to the total number of electrons incident upon the object.

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